Telephone for long distances or for deaf persons.



R. LAGUS.

TELEPHONE FOR LONG DISTANCES OR FOR DEAF PERSONS.

APPLICATION men MAR. 21. 1913.

Patented Sept. 11, 1917.

2 SHEETS-SHEET 1 WITNESSES:

.R. LAGUS.

TELEPHONE FOR LONG DISTANCES OR FOR DEAF PERSONS. APPLICATION FILED MAR.21. 1913.

1,239,702. Pmntea. Sept. 11, 1917.

2 SHEETS-SHEET Z. 1 9 B lNV ENTOR WITNESSES:

ROBERT LAG'US, 013 ABC, FINLAND, RUSSIA.

TELEPHOME FOR LONG DISTANCES OR'FOIt DEAF PERSONS.

1,239, 7&2.

Specification of Letters Patent. Patented Sept. 11, 1917,

Application filed March 21, 1913. Serial No. 755,898.

To all whom it may concern:

Be it known that Q, ROBERT LAGUS, a subject of the Emperor of Russia,residing at Abo, Finland, Russia, have invented certain new and usefulImprovements in Telephones for Long Distances or for Deaf Persons, of

which the following is a specification.

The present invention aims at enlarging the application of an ordinarytelephone in operation betweenplaces widely separated from each other byproviding an auxiliary apparatus so that conversation can be carried onwith the telephone over much greater distances and with substantiallygreater clearness than is possible without this auxiliary apparatus.Moreover, the auxiliary apparatus can be employed for the purpose ofstrengthening the sounds at the farther telephone, if two telephones areembraced in the same line, and it renders the use of the telephoneapparatus possible also for deaf people (over correspondingly shorterdistances than for persons with normal hearing of course). The inventionis based upon a proper combination of an ordinary telephone apparatuswith the hearing device for deaf persons constructed according to theprinciples of a telephone.

As is well known, most telephone apparatuses are so arranged that twolistening tubes can be attached to the same, and these are connectedeach with its pair of poles. In the present invention the listening tubefor ordinary telephone conversations is connected. to the one pair ofpoles, while the auxiliary apparatus is' united with the second pair ofpoles. The telephone is, so to say, transformed into a double apparatuswhich, according to the manner of switching in, is either in conditionto serve those of normal hearing for conversation over shorterdistancesor in condition for deaf persons over shorter distances or (and mostimportant) for those with normal hearing over substantial distances.

The attached drawing illustrates several embodiments of the invention.

Figure l showsin front elevation the new device attached to a walltelephone of ordinary construction;

Fig. 2 shows the same inside elevation and with the contact pieces andswitching device of the auxiliary apparatus partially in section andseparated from the contact pieces of the ordinary contact apparatus inorder .to show the manner of connection between both;

Fig. 3 is a vertical section through the box in which are the attachedreceiver of the ordinary telephone and the sound receiving andtransmitting microphone of the auxiliary apparatus; a

Fig. 4: is a vertical section through this casing seen along the lineA-B from left to right;

Fig. 5 is a second vertical section through the same box looking alongthe line C-D from right to left;

Fig. 6 is an elevation of the receiving microphone, the cover andmembrane being removed; 1

Fig. 7 is the end elevation of the device represented in Fig. 3 formovingthe receiving microphone;

' Fig. 8 illustrates a modification in detail of Fig. 1.

Referring to the embodiments of the invention illustrated, 1 is anordinary wall telephone, and 2 is a combination transmitter and receiverconnected with a pole couple 3. To a second pole couple 4 the auxiliaryapparatus is attached, andthis consists of a listening devicefor deafpersons, constructed according to the principles of a telephone.

- The connection in the arrangement illustrated is carried out in thefollowing manner. To the pole couple 4 there is attached a microphonereceiver 5 by means of the conductors 6 and 7. The sounds coming out ofthis microphone receiver 5 are received by a microphone transmitterscrewed onto the receiver or fastened to the same in any other manner.They are represented diagrammatically in Fig. 2 as separated from eachother. They may be fastened in various ways, as for example in theadjustable fashion of Fig. 8. The microphone transmitter-8 is connectedby means of a conductor 9 with a dry battery 10, of say 4 or 5 voltselectromotive force, and by means of a conductor 11 with a listeningtube 12, and

vided with a tune l4 screwed thereon and adapted to be inserted into theear for the purpose of a better conduction of the sound.

By means of any usual or suitable devices (not shown in the drawing) thebattery 10 may be cut out of the circuit when the apparatus is not inuse by hanging the listening tube 12 on the hooked arm 15. There areemployed for this purpose preferably the same devices as are generallyemployed with telephones.

Means are provided for uniting the receiving microphone 5, if necessary,completely with the listening tube or separating the same from eachother. A number of rather small conical holes are formed in the cover ofthe receivin microphone, which holes lie in a circle a out the usuallarge hole in the middle. These improvements render possible theapplication to the hearing apparatus of much stronger electric batteriesthan formerly, whereby a corresponding increase of the transmittedsounds can be obtained.

The receiver of the ordinary telephone is designated by 5 and thereceiving microphone by 8. They are arranged opposite each other in aprotecting box 16 with the geometrical axes in one and the same line.The receiver 5 is fastened rigidly in the left portion of the casing ina manner not indicated further in detail. Opposite the receiver 5 thereis arranged the receiving and transmitting microphone S in such a mannerthat the same can be adjusted toward and away from the receiver 5 bymeans of a screw 17. The screw 17 extends through the back of the casingand is engaged by a nut 18 held in place by a strap 19. As the nut isturned upward or downward the screw 17 is advanced or retracted. Thehook' 15 shown in Fig. 1 may be journaled upon the nut 18,

As shown in the drawing, the transmitting microphone 8 shows somedeviation from the ordinary microphone. It has a cover 20 with the usuallarge hole 21 in the middle and with a number of smaller holes 22arranged approximately in a circle about the large hole. In thepreferred arrangement, as illustrated, the holes 22 are arranged in twoconcentric circles around the middle hole 21. These holes 22 are conicaland, contrary to the middle hole 21, diverge toward the membrane disk23, as in calling tubes. The sound waves consequently reach this disk 23both through the iarge central and alsothrough the surrounding smallerholes and in various ways. At the back of the membrane disk 23 there isprovided a felt disk 24, the form of which, for example, can resemblethat of a wheel with six spokes (see Fig. 6). This division correspondsto the division into six parts of the carbon pieces 25 in the usualmicrophones. The

sounds than such a one without holes 22 and without felt disk 24. Theapplication of a felt disk behind the membrane disk is not new, but itis new to divide the felt disk in a manner corresponding to the numberof holes.

Both improvements, first the displaceability of the transmittingmicrophone 8 with relation to the receiver 5, and second the providingof the receiving microphone with the new cover 20 and the described feltdisk 2%, allow the application'of much more powerful batteries than wasformerly possible. Hitherto a potential of three volts was considered asthe highest applicable potential for the battery. Further increase ofthe potential gave no advantage, since at the same time disturbingconcomitant sounds arose which made impossible an understanding of thetransmitted speech sounds.

With the aid of the present improvements one can employ much strongerbatteries and at the same time perfectly control the sound, by adjustingfrom time to time the distance of the receiving microphone from thelistening apparatus; whereby conversation is rendered possible over muchgreater distances than formerly.

According to the construction indicated in Fig. 8 there are two hearingdevices indic'ated at 8 and 8" arranged in series and the number of suchlistening devices may be still further increased.

The suppression or weakening of the disturbing harmonics is effected ina very peculiar way. The hole 28 in the listening telephone held to theear is covered on its cable to varying distances, comprising a re-'ceiving device inserted in a branch from the circuit of said telephoneand amagnifying means detachably attached to said receiving device andmagnifying the sound received therein, said magnifying means comprisinga membrane and a cover located on the side of the membrane toward saidreceiving device and having a number of small holes through it, saidholes being flared toward Means for rendering a telephone appli cable tovarying distances, comprising a re-. ceiving device inserted in a branchfrom the circuit of said telephone and a magnifying means detachablyattached to said receiving device and magnifying the sound receivedtherein, said magnifying means comprising a membrane and acover locatedon the side of the membrane toward said receiving device and having anumber of small holes through it, said holes being flared toward themembrane, a felt disk on the other side of the membrane and having holesin it in line with the holes in the cover, carbon powder located in saidholes in the felt disk, and means for adjusting said receiving deviceand said magnifying device toward and away from each other. Y

3. Means for rendering a telephone applicable to vvarying distances,comprising areceiver and a second receiving device inserted in a branchfrom the circuit of said first receiver and a magnifying meansdetachably attached to'said receiving device and magnifying the soundreceived therein, said magnifying means comprising a membrane, a sourceof current of suitable strength for rendering audible currents of feeblestrength received from a long distance, and a cover located on the sideof the membrane toward. said receiving device, and means for adjustingsaid receiving device and said magnifying device toward and away fromeach other, in order to render distinct sounds received from distancesless than the extreme =distan'ee to which the strength of saidsource ofcurrent is suited;

In wltness whereof, I have hereuntosigned my name in the presence of twosubscribing witnesses.

ROBERT LAGUS.

